Microplastics in human blood may be overstated, researchers find
A University of Queensland environmental chemist says lab contamination and false positives have inflated reports of plastic in the human body.
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Published research suggesting microplastics are accumulating in human blood may be overstating the problem due to laboratory contamination and false positives, according to new peer-reviewed analysis.
Cassandra Rauert, an environmental chemist at the University of Queensland, has spent years investigating the presence of microplastics in human tissue. Her work revealed that current detection techniques are vulnerable to contamination from lab equipment—everything from construction materials, pipettes, and petri dishes to clothing and air.
In a recent paper, Rauert published a more significant concern: lipids (fats) present in blood can produce false positives for polyethylene, the most commonly produced plastic. Because lipids and polyethylene are made of identical building blocks, laboratory instruments can mistake a fat signal for plastic when the data are not carefully scrutinized.
Rauert and her team identified this issue in at least 18 previous studies on microplastics in human blood. To reduce contamination, they painstakingly rebuilt their lab workspace using glass and steel instead of plastic equipment.
The findings underscore how new the field remains. Rauert says researchers initially adapted analytical techniques developed for other purposes, rather than creating methods specifically designed to detect plastics in human tissue.
"I don't think we've got really good evidence at all for what effects [microplastics] might be having," Rauert said. She also addressed the widely cited claim that people consume a credit card's worth of plastic each week: "That has absolutely been debunked."
Once researchers can accurately measure microplastics in human tissue and blood, they'll be better positioned to determine what health effects, if any, plastic pollution is actually causing.
